A method for long-term micropropagation of Phaseolus coccineus L.

A method for long-term plant regeneration of Phaseolus coccineus L, is described. Shoot-tips and cotyledonary nodes cultured on a Murashige and Skoog medium supplemented with N(6)-benzylaminopurine, 10 μM, and α-naphthaleneacetic acid, 1μM, formed multiple bud-shoots. These shoots were transferred to medium containing BAP 1 μM, NAA 0.1 μM, and gibberellic acid 3 μM to promote shoot growth and further shoot multiplication. Rooting was achieved in medium with 11 μM indole-3-acetic acid. Rooted plants grew to maturity and were fertile. Cultures have maintained their ability to regenerate plants for more than two years. A sample of 30 regenerated plants (R0) was tested for chromosome number, all of them being diploid; seven isozymatic systems were electrophpretically analyzed in 82 R0 regenerated plants. No differences were observed in their electrophoretic patterns in comparison with those shown by seedlings. Histological studies revealed the origin of buds from calluses via organogenesis.